Considered the crossroads of ancient civilizations, the Mediterranean basin has nearly 250 million people in 25 countries, with a common climate called "Mediterranean", and a characteristic landscape. The streams flowing through it are important and varied.

The Mediterranean has always been an area of contact between civilizations, economies, and unevenly developed societies, thus imparting a certain amount of unity. This sea, is almost closed to the west by the Strait of Gibraltar, has an inland sea. Wide (2.5 million km2), it is also quite narrow, since only 140 km separate Sicily from Tunisia.

Transit area between the Atlantic and Indian Oceans, is one of the busiest seas in the world. Topped by mountains, its shores are narrow plains where populations are concentrated. The shores of the Mediterranean are generally highly urbanized, a trend reinforced by the tourism boom of the twentieth century.

Is this sea a border that is emblematic of the global divide? Does the interface appear as a link between two worlds?